1. Field of the Invention
In technical specifications associated with the third generation partnership project (3GPP), the definition of long term evolution (LTE) systems and devices continues. Certain embodiments of the present invention are generally related to methods, systems, and devices that can provide transitions between GSM/EDGE (Global System for Mobile communication, Enhanced Data rate for GSM Evolution) radio access networks (GERAN) and evolved universal mobile telecommunication system (UMTS), long term evolution radio access network (E-UTRAN/LTE) in order to provide seamless mobility across different technologies.
Handovers between GERAN and E-UTRAN/LTE technologies with a minimum of service disruption may be desirable in the development of such technologies. Both high QoS (Quality of Service) requirements of LTE technology and various inter-operability among the numerous technologies are important, and their maintenance is desirable.
2. Description of the Related Art
Handover of a circuit switched (CS) voice call to a E-UTRAN voice-over-Internet-protocol (VoIP) call and vice versa can be challenging. There is currently no circuit-switched domain in E-UTRAN, and interfaces to the circuit-switched domain are lacking. Certain embodiments of the present invention, therefore, are directed to performing the handover of a circuit-switched voice call to a VoIP call from GERAN to E-UTRAN in a seamless manner, without any service disruption or degradation. There are currently no suitable solutions to this problem.